Improvement in machines for bending wood



METERS, PHOTO LTHOGRAF WASHINGTON n C dimite-d tttrt parte entre LettersPatent No. 111,855, dated February 14, 1871.

IMPROVEMENT IN MACHINES FOR BENDING WOOD.

The Schedule referred to these Letters 1 atent`axxd making p axt o thesame.

To all whom it may concern :v Be it known that I, OBADIAH MARLAND, ofBoston, in thc county of Suffolk and State of Massachusetts, have'invented an Improvement in Chains for Bending Wood; and I do herebydeclare that the following, taken in connection with the drawing whichaccompanies and forms part of this speciication,.is a description of myinventionsucient to enable those skilled in the art to practice it.'

. Prior-to my invention wood has been bent by first confining it to aiiat Aband of ironor toQa fiat thin chain, the baud or chain havingthereon at one end a chock, and .at the other a piece with set-screws,which- `were adjusted tightl'yragainst one end of the timber,

forcing the other end solidly against thelchock; then. both the timberand the band or chain were bent by suitable application of force.

In bending Atimber the end sought is to keep the fibers of the extradosof the wood while exing, and

when' dexed 'in their natural condition as to extension or compression',as if they are extended they will rupture, and if they 'are compressedthen the amount of compression will be inj nrions and unnecessary.

When tw'opieces of material in paralleifstraight lines Aare bent intoparallel curves, with their ends so secured together' that they cannotmove relatively toV eachother, the `tendency will-be toelongate theouter lines of the combination and to-shorten the inner lilies,- andthere will be one'line betweenfthe extrados and intrados of the curvewhichwvill remain of the same length which it had beforebending, whichline may he termed the neutrailine'.

New when, as before my invention, a flat meta band or a dat chain hasbeeny used the neutral line has been about in the center of thethickness. of the band or inline ofthe pivots of the chain, and thetimber has been compressed on the extrados, though not of course to thesame extent as at the intrados, and the exteriors of the band and chainhave been elongated and their interiors have been compressed, resultingin breaking the band and in shearing oi the chainpivots.

In practice I am informed that chains so appliedhave been destroyed atthe first bending with a timber, and the bands break upon the second orthird bending.

My invention consists in details of construction and arrangement,hereinafter described, of chains for bending timber, in which chains onesurface of each link- 'oar bonds or turns practically in a iine orsurface coinciding with lines drawn across the back or outer surface ot'the timber to bo bent, Y

Of the drawing- Figure l shows, in plan, a timber-bending chainillustrating my invention.

Figure 2 is a central longitudinal` section of the x same, th'e sectionbeing taken in the piane of the line s s fio'. y 7 D Figure 3 is a sideview of the chain.

Figures 4, 5, 6, and 7. are' sectional views of portions of chainembodying my invention as they appear when bent or curved, each viwexhibiting a modification in the detail of construction, though all ofthem shows that the bending takes place in lines coincident (orsubstantially so) with the back of the timber to be bent-,in combinationwith thechain.

Included with each of figs. 4, 5, and 6 is a longitudinal sectional viewof one end of'one bar of the chain.

Figure 7 includes a plan as weli as a longitudinalV sectional view. ofone end of a bar.

. Figure S includes three .views of pieces used with the chain, as showninhg. 6, which pieces .I term Spanner-bars. r

Figure 9 shows a detail of construction. Figure l0 shows, in end view,three bars of a chain, each witha half pivot on each side', `and withawhole reinforcingpivot 'located near lthe back and in theccntrallongitudinal plane of the bar..

The chain shown at fig. 7 corresponds, substantially, with that part ofAthechain shown in' iig. 2, where marked 2 1 2. A

'Iihe chain shown in fig. 6 corresponds, substantially, with 'that partofthe chain shown'in iig. 2, where marked 3'4 5.

The'chan shown in iig. 5 corresponds, substantially, with that part ofthechain shown Anfig. 2, where marked 6. In practice I-prefer to makethe bars'of my chain of uniform width, as seen in ig's. 4, 5, 6, and 7,and n ot as seen inv igs.l 1, 2, and 3, where the variations in widthwere made merely to enable me to pass in one chain from bars of one kindto bars of another kind while keeping radius links, c, of the samelength.

The bars lt are made with flanges, b, oneach end,

projecting beyond the neutral piace or'the draft-piane toward thecenters of. the curves to be formed, these anges serving to keep thetimber from spreading sidewise as it is bent; for it' the timber is toonarrow to iill the. space between the anges, then. side pieces aredriven between the angesV on one side of the chain and the side of thetimber.

The chain has secured to il, at' suitable apart, two-.stout chocks orclamps, one or both of which are provided with set-screws, so that byadjustmentthereof no endwise movement of the whole timber, vwithrelation to the chain, can take place.

This is not shown, as it does not differ from the provision heretoforeused with metal bands for the same purpose.

Each bar, et, is made with projecting pivots, by which it is secured tothe bars adjacent by suitable The bars 2 l 2, in figs-1, 2, and 3, andthe bars seen in gs. 7 and 10 have on each edge a half pivot, the axesof. which are in lines formed bytheinterdistances v as before described.v

The chain shown in g. 4 is like'that seen in iig. 6,:

. sections of the sides ofthe bars with the timber faces thereof', andit will be seen that all parts of my chain,

seen .inig 3, vto'strengthen the chain when used for heavy work.

It will-be seen that the line a; cr, which is in the.

timber-face of the chain and is the neutral'line and the line of draft,is ofthe same length whetherexed orstraight.-

The chain shown in g.'6.is substantially the same 'as that part of thechain shownat 3 4 5, g. 2,Y except where the construction in'g.2 ismodified to enable me to pass from one forni to another. Here, theflanges b extend further from the bodies of the bars c than they do infig. 6. This'enables me to make use of" Spanner-bars d, which span orbreak the joints between the bars d, 'and are of such thickness thatthey form the timber-face in the line of' the axes of the pivots, whichpivots are whole and are located with their axes in the central planesof each bar denotedfby the line y y.

' Where heavy bending is to' b edone, two pivots may bemade on each end,of said` bars andunited bylinks, as seen at 3 and 4 in iig. 3, for thepurpose of strengthening the chain.

The Spanner-barsl d are made onf-the timber-face, between the lines d11. of a width equal to the dis# Ytance fot' the pivots apart, and areso, located on the bars a. as to .bring the lines d (Z into continuationof 4-the axial lines of the pivots.y

. The edges of the Spanner-baremo beveled and notched, as shown mostclearly in Iig. 8, and the parts c, and the edges of the endSpanner-bars abut against suitable formations in or on the chain, asseen in g.2, so that the spanner=bars 'dc not move reiativelyv to thelength of the chain.

The chain shown in fig. 5 is made up of "bars substantially like thoseshown at 6 6, iig. 2.

The pivots on these b ars have their axes at or very ,neartheintersections of the faces of the bars be tween the i'anges 11, andsections taken in planes indicated by the line w w.

With a'chain vs o'niade, a thin metal band may be laid' between the'timber and the bars, where it wil,.

if carefnll y proportioned as to thickness, with reference to the 'curveto be'bent andthe exact relation of the axes of the pivots to the' facesof bars a, average the spaces between the angles of 'the the bai-sa andthe inscribed curve.

f This band does not receive either compression or extension in the actof beiiding, as its ends are not fixed, and as it is simply flexed itwill last almost indenitely.

If used for heavy bending, the bars maybe made deep and with reinforcingpivots and connecting-links,

except'that Spanner-bars are not used, and on each polygon formed -bybar a filling-piece, f, is used, the face of which is brought into theline of the axes of the pivots.

lhese piecesfmay be curved on the face to suit the curvel to be formedon the timber, `and chains lso made, or asy shown in4 fig. 5are bestadapted to light work.

to suit larger orisriialler curves, and by slight changes arranged to beflexed, and to said parts are secured the chocks, clamps, or pieceswhich take the end-th rust of the timber when it is bent.

The end'bars at 6 6 'in fig. 2 have-their pivots connected by links, c,to pivots 'on the pieces g, whichpivots are strengthened byconnectinglinks taking hold-of their outer ends and extending over othershort pivots or studs formed on said pieces g at h.

In the centei` of each piece g is formed a bearing inay extendoutwadbeyond the trnnnions as fitras required for convenience inmanipulating and securing the timber.

It is tothese pieces j' that the clamps, which secure the timber ends,are fixed, and as the pieces j can turn will thereby be equalizedbetween the pivots and links ou both sides of the chain. w g" l Theouter lines of -links c connecting the pivots are made' in halves, andenter grooves turned near the eudsof the pivots, and said halves beingscrewed-together prevent all or any oil the links c from becomingdetached.

In fig. 9 is seen one of the short pivots on the piece g', seen at h,iig. 1, showing a convenient way of sec ur;- ing the link on the pivot.

In the pivot a groove is turned beyond the link, into are secured by anouter ring p, the space between said outer ring'and the capover the endof the pivot being filled bythe ring q, the cap fr being secured to thepivot by a central screwi- The trunnion i. is secured in place `by acap, u, which 'tits in a recess turned to receive it, the cap being helding through the trunni'on.

I claimf v 1. lhe combination of bars a, by means of ha'lf pivots andlinks, substantially as described.

2. The combination, with bars a, of ltwo sets of piv- :ots and links,one on which/the bars turn, and the other for reinforcing the'fformer.

3. The combination, --with the bars met' Spanner-bars or pieces j,substantially asandfor the purpose speci- 4. The spanner-bars al, withnotched and beveled edges, and 'with their backs curved at the edges,substantially as shown in g. S.'

5. '.lhe combination, with a chain made up of bars c connected attheir'ends, of clamp-bearing pieces j, by means of trunnions, arrangedsubstantially as and for the purpose set forth.

OBADIAI-I MARLAN D.

tothe trunnion byscrews entering it, or by bolts pass- Witnesses J.nossrmn,

J. B. CROSBY.

The pieces f can be changed for others having faces in the thickness maybechanged slightly in position receive and support -the timber, which,parts are not l for a trunuion, i, which is. made on the piece j, whichonvtheirtrnnnious it will be obvious that the strain:

which groove hall' rings, o, are placed, which haii" rings

